The launch vehicle or booster rocket stages presently in use with liquid propulsion systems include a series of components that fulfill various different functions. This includes tanks for storing fuel and oxidizer, whereby the fuel and the oxidizer are stored either in separate tanks or in one tank with a partition separating wall between fuel and oxidizer, as well as a so-called engine thrust frame, designated as an Engine Thrust Frame (ETF) in English. The latter transmits the loads of the engine into the tank and into the primary structure on the one hand, and the loads of the launcher or booster via the primary structure into the tank and the engine on the other hand. Conventionally, the engine thrust frame is separate from and external to the propellant tank(s), and e.g. extends externally around the tank from the engine to the primary structure so as to transmit forces from the engine to the primary structure and vice versa. Furthermore, such rocket stages include propellant handling or management devices, designated as Propellant Management Devices (PMD) in English, which serve, among other things, for ensuring the supply of gas-free and particle-free propellant to the engine even when there is only a minimum remaining propellant residual quantity, or for suppressing the spinning of the liquid. It is desirable to reduce the size, mass and complexity of the overall structure in order to reduce the cost, increase the payload capacity and/or allow the shape and configuration of the rocket stage to be optimized.